1. Field of the Invention
The present invention is directed to a therapy method and apparatus for treatment of a patient with focused acoustic waves of the type having a source of focused acoustic waves, means for receiving echoes of the acoustic waves reflected from a subject to be treated, and means for switching the apparatus from a locating to a therapy mode.
2. Description of the Prior Art
Non-invasive acoustic therapy systems are utilized, for example, for the disintegration of calculi (lithotripsy), for treating tumor pathologies (hyperthermia) or for treating bone conditions (osteorestoration). The received, reflected parts of the acoustic waves are employed for locating the region to be treated. For example, the chronological relation between the generation of the acoustic waves and the reception of their reflected parts is utilized to judge whether the region to be treated is located in the focus of the acoustic waves. When the chronological allocation indicates a position of the region to be treated outside the focus, the source of acoustic waves and the subject to be treated are displaced relative to one another such that a chronological allocation is achieved that indicates the region to be treated is in the focus of the acoustic waves.
German OS 27 22 252 discloses such a therapy system for use with the disintegration of calculi on the basis of shockwaves. In this therapy system, reduced-energy shockwaves are generated during locating mode. Damage to the tissue surrounding the calculus to be disintegrated during the locating procedure is prevented in this way. The parts of the shockwaves reflected from the subject to be treated are received with a plurality of broadband pressure sensors. The output signals of the pressure sensors, however, do not allow the region to be treated, i.e. the calculus, to be exactly positioned in the focus of the acoustic waves under all circumstances.